Final answer:
The sound [b] is spelled 'b' or 'bb' in English; 'b' is most common, but 'bb' appears when followed by 'le' after a short vowel. The compound words 'cupboard' and 'raspberry' are exceptions. Underlining the letters in words showcases the spelling of the sounds [b], [t], and [d].
Step-by-step explanation:
The sound [b] has two common ways of being spelled. In English, [b] is typically spelled as b, but when followed by le after a short vowel sound, it is usually spelled as bb. Words such as able, scribble, and resemble contain the [b] sound with different spellings. Furthermore, the compound words cupboard and raspberry are unique exceptions in the English language where [b] is not spelled with a b or bb.
To demonstrate understanding of this concept, let's sort specified words into two groups based on their spelling of the [b] sound:
Words with [b] spelled b: able, resemble, noble, gamble
Words with [b] spelled bb: pebble, tremble, bubble
The word scribble belongs in both groups because it has the [b] sound spelled as bb following a short vowel and le.
Lastly, to underline the letters that spell the sounds in given words:
Underline the letter b in the word behind.
Underline the letter t in the word itself.
Underline the letter d in the word wonderful.